You didn't mention your database version but I'm guessing it must be SQL 2000 not SQL 2005.
There is one place in the script that I found that I think is a problem for SQL 2000. SQL 2000 doesn't like to use any aggregate functions like "SELECT TOP 1 ..." if you are selecting a text or ntext field.
If you open the script in a text editor (/Setup/applications/mojoportal-core/SchemaInstallScripts/mssql/18.104.22.168.config and search for "mp_ModuleSettings_SyncDefinitions", you will find the offending procedure. The problem statement within the procedure is:
SET RegexValidationExpression = (SELECT TOP 1 mds.RegexValidationExpression
FROM mp_ModuleDefinitionSettings mds
WHERE mds.ModuleDefId IN (SELECT ModuleDefId
FROM mp_Modules m
WHERE m.ModuleID = mp_ModuleSettings.ModuleID)
AND mds.SettingName = mp_ModuleSettings.SettingName
mds.RegexValidationExpression is an ntext field and this poses a problem for SQL 2000. I'm not sure of a good solution. You can chop out that part of the script and it should be able to complete the installation and the site will work, but some of the validation expressions for module setings will be missing or at least it won't be possible to change them on upgrades. I think this procedure is only invoked during upgrades.
If you have any ideas for a good solution I'd be glad to hear them, otherwise I think we may be getting to the end of the line for SQL 2000 support.
If you have SQL 2005 or SQL 2005 Express available I would use one of those.
Hope it helps,